Thermal treatment of painted metal objects is the suspected source of unsafe levels of PCBs in soils at Badger Army Ammunition Plant. Following the detection of high levels of PCBs in paint on pipes, flanges, and other metal objects, CSWAB asked state regulators to require environmental testing for PCBs at the site of a former Decontamination Oven – a facility used to thermally treat metal objects for explosive contamination. Resultant particulates and fumes from the oven were released directly to the open air with no treatment or emissions controls.
Recent testing by the Army has detected Aroclor 1254 (a commercial PCB mixture) in soils at levels as high as 740 ug/kg, exceeding the EPA Region 9 Residential Preliminary Remedial Goal (PRG) of 220 ug/kg and “right at” the EPA Region 9 Industrial PRG of 740 ug/kg.
The Wisconsin Department of Natural Resources (WDNR) confirmed that temperatures in the decontamination oven were sufficient to volatize PCBs and other contaminants. In a reply to CSWAB, the WDNR wrote: “The primary PCB Aroclor used in paint was 1254 … under heating at 450 degrees Fahrenheit it is likely that the Aroclor 1254 did volatize out of the paint.”
Human exposure to PCBs is a concern because of the wide range of adverse health effects including skin irritation, reproductive and developmental effects, immunologic effects, liver damage, and cancer. The developing fetus, infants, and children are the population groups most vulnerable to exposure. Exposure may impede the development of their brains, reproductive, immune, and endocrine systems.
In the past, paint manufacturers used from 5 to 12 percent PCBs in paints as a plasticizer. According to the Washington State Department of Ecology, lead, mercury, cadmium, and chromium were commonly used in paint as pigments and preservatives and are found in paint on older buildings. Arsenic was used as a pigment, a wood preservative, and as an anti-fouling ingredient. Barium was used as a pigment and a corrosion inhibitor. Old latex paint produced before 1992 may also contain mercury which was added as a fungicide.
The Army is anxious to start up a new facility but first needs approvals from the EPA and WDNR. The new decontamination oven, which is somewhat smaller than the original, operates on the same principal as the old facility and has no air emissions controls. In the meantime, the WDNR has asked the Army to “set aside” any waste that may be contaminated with PCBs.